The support network for Britain’s special forces is facing major cutbacks with
around 600 posts earmarked to be lost in a reorganisation to coincide with
the military pull-out from Afghanistan.

Sources told The Sunday Telegraph that the controversial move could become necessary because the campaign had seen a build-up of support and logistics to enable elite squads to carry out their operations which would no longer be necessary.

The proposals, drawn up at the Ministry of Defence, do not affect the fighting troops of the Special Air Service or the Special Boat Service.

However 156 posts are expected to be lost from the Special Forces Support Group, which provides infantry and specialised support to SAS and SBS operations. The rest of the 600 posts are from units providing vehicles, signals, logistics and intelligence — the key “enablers” which allow elite troops to operate.

The plans come in the wake of last week’s confusion over the Coalition’s plans for future overall spending on defence.

David Cameron suggested that totals would be increased “year on year” from 2015, following the next Whitehall spending review. But Philip Hammond, the Defence Secretary, later said the increase would apply only to equipment.

Mr Hammond today opens up a new rift with the Liberal Democrats over the future of Britain’s independent nuclear deterrent. He uses an article in The Sunday Telegraph to back a like-for-like replacement of the current Trident submarine system as “the best option for Britain”.

He warns that alternative systems being studied by the Liberal Democrats would carry “enormous financial, technical and strategic risk” — and could even risk triggering a nuclear war.

Sources said the cuts proposed to special forces support were “an option being considered by the military” because certain roles would not be needed after the withdrawal of British troops from Afghanistan, scheduled to take place by the end of 2014.

The Government never comments officially on the special forces, whose total numbers are thought to be about 2,000. In the 2010 Strategic Defence and Security Review, special forces were spared cutbacks which overall saw the defence budget fall by around 7.7 per cent to around £33.5billion a year between 2010-11 and 2014-2015.

Some military figures are unhappy about the latest plan. One said the decisions in the SDSR would be “completely undermined” if it was implemented and added: “This is absolutely bonkers — it will institutionalise overstretch within the UK’s special forces at a time when they have been operating, and need to continue to operate, at a high tempo.”

Jim Murphy, the shadow defence secretary, said: “These very specialised, high-end forces, which the UK now needs more than ever, are being made redundant at the same time as ministers hail their importance. Prime ministerial promises to support defence seem even more worthless.”

Mr Hammond, meanwhile, backs moves to keep a continuous nuclear deterrent at sea. It offers Britain more “freedom of manoeuvre” in a crisis, while the Trident missile system provides “range” and “endurance”, he argues.

Replacing Trident would cost around five to six per cent of the annual defence budget, which would be “affordable” and would enhance links with the US, which uses the same system, according to Mr Hammond.

His comments come days after Danny Alexander, the Lib Dem Treasury Chief Secretary, said a direct replacement for Trident was “not financially realistic”. Mr Alexander took charge last year of the Government’s review into alternatives to a like-for-like Trident replacement. The review was obtained by the Liberal Democrats as part of the Coalition Agreement shortly after the 2010 general election.

The agreement allowed the Lib Dems to “make the case for alternatives”, although it committed the Government to “maintain Britain’s nuclear deterrent”.

Mr Hammond, backed by a large majority of Tories, wants a direct replacement for the current Vanguard submarines, which are expected to be decommissioned in the late 2020s. Their Trident II D-5 missiles are expected to remain in service until 2042.

The Government is spending £1.4billion on initial design work for replacement submarines — a clear signal that a like-for-like system will go ahead. But the final decision is not due until 2016, after the next general election.

Last month, Mr Alexander said MPs from all parties, as well as senior military officers, should accept there were “credible and compelling alternatives” to continuous at-sea deterrence and the Treasury did not have a “magic pot of money” to pay for a new generation of submarines.

Mr Hammond’s article reflects a concern among senior Tories that the Lib Dems are trying to “move the goalposts” in an attempt to redefine what is needed and to pave the way for a part-time deterrent when the review of alternatives makes its final recommendations.

A replacement system based on cruise missiles, understood to be one of the alternatives favoured by the Lib Dems, as well as some senior military figures, would mean designing new warheads and missiles from scratch, Mr Hammond argues.

He writes: “A deterrent only deters if it is credible and available. All the evidence points to a continuous-at-sea presence, based on Trident, as the most cost-effective route to deliver the deterrent effect.

“A cruise-based deterrent would carry significant risk of miscalculation and unintended escalation. At the point of firing, other states could have no way of knowing whether we had launched a conventional cruise missile or one with a nuclear warhead. Such uncertainty could risk triggering a nuclear war at a time of tension.